The "native resolution" is written in a monitor's specifications, but what exactly does it mean? What happens if images are displayed at a resolution other than the "native resolution"? In particular, you can't help wondering what happens when an image is displayed in a resolution with a different aspect ratio.

The "number of pixels", or put another way "the number of points that light up", in an LCD screen is decided, and this "number of pixels" is the "native resolution." For example, this means that a monitor with a native resolution of "1920 × 1200" lights up, or turns off, 1920 horizontal rows (dots) and 1200 vertical rows (dots) of pixels to display images.
Then what happens if an image is displayed in a different resolution from the "native resolution," and in particular what happens if that resolution has a different aspect ratio to the "native resolution"? Let's consider a case where a "1280 × 1024" (horizontal : vertical = 5:4) image is displayed on an LCD monitor with a native resolution of "1920 × 1200" (horizontal : vertical = 16:10).

When a 1280 × 1024 image is displayed on a monitor with a native resolution of 1920 × 1200

Normal display (same magnification)
In normal display (same magnification) the image with a resolution of 1280 × 1024 is displayed with that number of pixels. In other words, 1280 horizontal rows and 1024 vertical rows of pixels are used to display it. At that time 640 horizontal rows (1920 – 1280 = 640) and 176 vertical rows (1200 – 1024 = 176) are not lit up so black areas are created at the top, bottom, left and right.

Enlarged display
An enlarged display means that the image to be displayed is enlarged while preserving its "5:4" aspect ratio. In this case the vertical 1200/1024 is enlarged 1.171875 times, so the image is displayed using 1500 horizontal rows (1280 × 1.171875 = 1500) and 1200 vertical rows of pixels. By doing this the image is not distorted but black areas are produced at the left and right since 420 horizontal pixels (1920 – 1500 = 420) are not lit up. The image is also slightly fuzzier than in normal mode since it has been enlarged.

Full-screen display
With full-screen display the horizontal 1280 rows of pixels are displayed as 1920 rows, and the vertical 1024 rows of pixels are displayed as 1200 rows. This means that the image's aspect ratio, which should be 5:4, has been changed to 16:10. As a result, a circle, for example, is displayed as a horizontally elongated oval. The image is also slightly fuzzier than in normal mode since it has been enlarged.

Deterioration in image quality is inevitable if anything other than the "native resolution" is used.
As we have explained, when something like full-screen display or enlarged display is used to display an image on an LCD at a resolution other than the recommended one, it can be necessary, for example, to use two pixels to display data that should be shown with one dot. Naturally this leads to a loss of sharpness. Since such deterioration in image quality cannot be avoided, of course the best thing is to display an image at the "native resolution" for the LCD monitor.

Both the monitor and the video card have various resolutions, and we recommend that you bear in mind what we have said in this article and correctly adjust the monitor to put as little strain as possible on the eyes.

How to set the monitor resolution

Please check how to set your monitor's resolution. Select the OS you use.